MEGAN Fox is angry, hot and sometimes just off-the-rails mad — once threatening to kill on-again/off-again boyfriend Brian Austin Green. “My temper is ridiculously bad,” Fox, 23, confesses to Rolling Stone magazine for its October issue. “I’ve had to say to Brian, ‘You have to go and stop talking to me, because I’m going to kill you. I’m going to stab you with something, please leave,’ ” she claims. “I’d never own a gun for that reason,” says la femme dangereuse. “I wouldn’t shoot to kill. But I would shoot him in the leg, for sure.”